Thread:

New project with a question. 84 Cimmaron 16' 383 SBC

I'm curious on this one. I thought inversion issues presented differently than miked oil. I figured it would hydro lock if you were sucking enough water in to milk the oil. I'm sure others more knowledgeable than me will chime in shortly.

If it is milking the oil , it is most likely a intake gasket in my experiences.

I do know 100% for sure that the heads have been swapped out, the intake was checked, cylinder walls looked at, all new gaskets putting it back together, exhaust manifolds pressure tested, and also had liquid glass ran through it. The problem is still there. Yes, it does have a valve on the feed hose but I do not know what the pressure is. Is there any tests I can do before I have to start throwing money at parts it may or may not need? I really want to keep this boat low budget because I don't plan on keeping it for more than a year and I don't want to lose money on it. I am also not going to drive or sell a boat that milks the oil either!

Put a pressure guage on your thermostat housing and check the pressure at WOT. It shouldn't go much over 20 lbs. One from the local hardware store like for a water system on a well pump works just fine.

Duane HTP

Cool! Thanks for the help on this guys. I am still a total newbie to boats so I can use all the help I can get!

Originally Posted by Turbo Dan-O

yes it has a monster solid lift cam in it. It will also run all day hooked to a hose pipe out of the water and the oil will be fine. Only when you put it in the lake does this happen. So my question is how big of a cam can you run before you start to run into this problem?

You (and your friend) may have diagnosed your milky oil problem already , Small blocks simple and reliable in jets and seldom have any issues particularly water in oil or milky oil , however a "monster cam" may be at the root , most anything with log exaust cannot effectivley work with excessive duration at 50* exceeding 235 to 240 ,rule of thumb (causes water "reversion" via the exaust) , short overlap can be a problem as well Maybe be advised to gather cam specs and see what you have ? also simply missing exaust flappers, running without snails, and running on a garden hose (under some circumstances) can "milk the oil" call if we can help Tom

Using a pressure gauge is the best, but you could do it this way. Close your water valve all the way down, you will now know how open it was. Then open the valve one turn, take the boat out and run it at WOT and see it the engine starts to run to hot. If it does, add another half turn and run it again and again until you find the sweet spot. Keep an eye on your temp gauge when you idle for a long time, it will tend to heat up. Now remember how many turns you have in it in case you change it to put a hose on it. Again, a pressure gauge is the best but this will get you by.

Yes, the exhaust flappers are made out of cut up basket ball(true story) and are half missing anyway, also there are no "snails" on it either just a slight upward angle. I can see where water could get back in there especially on a hard slow down. Maybe put a pressure gauge on it and also get some cheap hardware store parts to keep the exhaust out of the water? Or could it still be sucking water back in where the water goes into the back of the manifolds to be dumped out? Looks like I still have some work to do...

Originally Posted by Turbo Dan-O

Yes, the exhaust flappers are made out of cut up basket ball(true story) and are half missing anyway, also there are no "snails" on it either just a slight upward angle. I can see where water could get back in there especially on a hard slow down. Maybe put a pressure gauge on it and also get some cheap hardware store parts to keep the exhaust out of the water? Or could it still be sucking water back in where the water goes into the back of the manifolds to be dumped out? Looks like I still have some work to do...

Picture?